Belt-tightener



(Nd Model.) n T L 2Sheetsj-Sheet BELT TIGHTENBR.

No. 472,967. Patented Apr. 121892.

mvm woz W 5 4 m1, wAsNma f EUNITED STATESPATE T \VILLIAM D. TYLER, OF DENVER, COLORADO.

BELT-TIGHTENER.

SPECIFICATION forming part of Letters Patent No. 472,967, dated April 12, 1892. Application filed July 24, 1891. Serial No. 400,64=8. (No model.)

To all whom it may concern: v

Be it known that I, IVILLIAM D. TYLER, a citizen of the United States of America, residing at Denver, in the county of Arapahoe and State of Colorado, have invented certain new and useful Improvements in Belt-Tighteners; and I do declare the following to be a full, clear, and exact description of the invention, such will enable others skilled in the art to which it appertains to make and use the same, reference beinghad to the accompanying draw ings, and to the figures of reference marked thereon, which form a part of this specification.

VMy invention relates to improvements in belt-tighteners for use where machinery located on one floor of a building is propelled bya power located on a fioor below. For instance, in electric-power plants of considerable magnitude many of the dyn'amos are often located above the first floor of the building, while the engine propelling them is placed on the first or lower door. The power is then transmitted from pulleys on a main shaft below, through the medium of suitable belts, to the pulleys on the armature-shafts on the dynamos. In tightening these belts, therefore, the dynamo, which is mounted upon a movable sliding frame, hasbeen moved in a horizontal plane to one side of a perpendicular line connecting the shafts upon which the pulleys are located. It will be observed that by this lateral movement in a horizontal plane the distance between the centers of the shafts is increased by the difference between the length of the perpendicular and the length of the hypotenuse of a right angled triangle, of which a line connecting the centers of the two shafts before movement would form the perpendicular, the line in which the center of the moving shaft has traveled thebase, and a line connecting the centers of the shaft after movement the hypotenuse. A considerable lateral movement has thus been found necessary in order to give the belts the desired tension,'and the greater this lateral movement the greater the space which must be allowed each machine in order to give room for adjustment. Hence for the purpose of economizing space it has been found desirable to tighten these belts without relying entirely upon the lateral movement of the overhead machines.

The object, therefore, of my invention is to object I accomplish by the use of the mechanism illustrated in the accompanying drawings, in which Figure 1 is a side elevation of the device, showing the overhead machines in place. Fig.

-2 is a plan view with the machine removed.

Fig. 3 is a fragmentary view illustrating a means of adjustment; Fig. 4, an elevation of my improved belt-tightening means.

In the views, similar reference characters indicating corresponding parts or elements of the mechanism, let the numeral 5 designate a dynamo, which may be considered typical of any suitable overhead machine provided with ashaft 6, upon which is rigidly mounted a pulley 7, connected through the medium of a belt 8 with another pulley 9, mounted upon a shaft 10, suitably journaled upon a floor below and driven by suitable power. The dynamo 5 is mounted upon a movable support or frame consisting of two beams 12, connected by suitable cross-bars 13. The upper surfaces of beams 12 lie in a horizontal plane, so as to support the machine in an upright position, while the lower surfaces of these beams form inclined planes engaging the oppositelyinclined faces of other beams 14, resting upon and rigidly secured to the floor 15. These engaging faces of the stationary and movable frame are oppositely shouldered, as shown at 20, in order to maintain the frames at all times in the proper relative position.

The movable frame may be adj ustedin any suitable manner, as by the screw-bolt, leverarm, ratchet, and pawl shown in the drawings. The screw-bolt 25 consists of a plain portion passing through a suitable aperture formed in a cross-beam 13 of the movable frame and adapted to rotate freely therein, and a threaded portion engaging a correspondingly-threaded nut 26, made fast to the stationary cross-beams 27 of the stationary frame 14. The outer extremity of the screwbolt is provided with the ratchet-head 28, rigidly secured thereto, and the movable lever-arm 29, provided with the pawl 30, pivoted thereon and adapted to engage the ratchet-disk. The screweboltoccupies a position parallel with the inclined engaging faces of the two frames. This bolt may occupy a position parallel with the horizontal faces of the frames; but in this case the nut 26 must have a vertical movement and be provided with guides. v It will be observed that by the use of the lever-arm, pawl, and ratchet the screw-bolt may be rotated. Now as the nut is stationary the bolt moves therethrough and carries the movable frame toward the right or up the inclined face of the stationary frame. In this case the dynamo-shaft, instead of moving in a horizontal plane, moves upward in an inclined plane, its path lying parallel with the inclined face of the stationary frame, and the advantage gained over a simple lateral movement will be readily observed. This advantage will of course depend upon the inclination of the engaging faces of theframes, and in any event will be the length of the per pendicular of the right-angled triangle formed by drawing a direct line from the original location of the center of the dynamo-shaft to the center of this shaft in the changed position and then drawing a perpendicular line from the last-named point to intersect ahorizontal line drawn from the first-named point. I11 this case the horizontal line will be the base, While the line in which the center of the shaft moves will form the hypotenuse of the triangle. machines may be correspondingly diminished and the same tightening result attained.

It will be observed that both the inclined Hence the lateral movement of the above the propelling-shaft, the combination f two frames having oppositely-disposed inc incd engaging faces, one of said frames being movable, an actuating screw-shaft, and a stationary support connected with the movable frame by the actuating-shaft, said shaft being swiveled in one of the connected parts and engaging a threaded socket in the other parts, and suitable means for rotating the actuating-screw, whereby the movable frame is shifted, substantially as described.

2. In a belt-tightener, the combination of two frames having oppositely-disposed inclined engaging faces, the upper frame being movable and thelower stationary, and an actuating screw-shaft occupyinga position parallel with the inclined engaging faces of the frames, said shaft being swiveled in the movable frame and engaging a threaded socket in the stationary frame, the outer extremity of the shaft beingprovided with a rigid ratch et-head and a movable lever-arm and engaging pawl, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

WVILLIAM D. TYLER.

Witnesses:

WM. MoCoNNnLL, G. J. ROLLANDET. 

